#include <iostream>
using namespace std;

struct point3d
{
    float x;
    float y;
    float z;
    float i;
};

int main(void)
{
    uint8_t data[64];
    struct point3d *p = reinterpret_cast<struct point3d*>(data);
    p->x = 1.0;
    p->y = 2.0;
    p->z = 3.0;
    p->i = 4.0;

    p++;
    p->x = 5.0;
    p->y = 6.0;
    p->z = 7.0;
    p->i = 8.0;

    cout << p->x << endl;
    cout << p->y << endl;
    cout << p->z << endl;
    cout << p->i << endl;

    return 0;
}